The present invention relates generally to medical devices and, more particularly, to a hinge for an orthopedic support for assisting movement of body limbs which are in an infirm or partially infirm state.
Devices of the type to which the present invention relate are normally referred to as "orthotic". This name is based upon the fact that such devices operate to support or assist injured or infirmed body limbs as opposed to replacing a missing limb. Accordingly, the term orthotic as used herein, is to be distinguished from the term prosthesis which is generally defined as an artifical device to replace a missing body part or limb.
The present invention comprises a type of orthotic device which operates by a pawl and ratchet, and resilient spring action, in order to permit certain discreet and limited rotational movement of portions of infirmed limbs relative to each other in a manner intended generally to simulate normal motion of such limbs. Such orthotic devices will, typically, comprise a pair of relatively moveable support members attached respectively to different parts of the body, for example, the upper leg and lower leg; in addition, some form of articulation means providing a resilient, or other controlled or controllable interconnection, between the proximal and distal parts of such a support device, are inherent in and appropriate to the operation of such devices.
For the operation of such devices, it is desirable that any artificial joint means, whether resilient in character or step advance rotational in character, comprise sufficient potency to assist in the effective functioning of the affected limb, while avoiding excesses of motion, or insufficiencies of motion, which might prove discomforting or injurious. Accordingly, a certain degree of adjustability, versatility, and the like in the motion of the functioning of such devices, is desirable.
Although the basic function of an orthotic device is to support a limb or limbs, it is desirable to attain, to the degree feasible, certain limited motion and flexibility in predetermined directions. Thus an objective in orthotic devices is the provision of the fundamental support function while, as an advantageous addition, the providing of versatility of motion that will, to the extent practical, resemble normal body motion. As an addition to enabling adequate support, versatility of motion, and adjustability to various positions, the orthotic device should be as simple as possible in its arrangement of parts so that ease of manufacture will be attained and the functioning of the device will be as unobtrusive as possible, from a cosmetic point of view.
The present and prior art, as best known to the inventor, is reflected in U.S. Pat. Nos. 2,557,604 (1951) to Invidiato; 3,732,861 (1973) to Lehneis; and 4,090,264 (1978) to Thompson. Also of interest is Italian Pat. No. 528,240 (1955) to Barberis.
The present technology is believed to be properly classified in U.S. Class 3, Classes 24 to 27; U.S. Class 128, Subclass 8; and U.S. Class 364, Subclass 569.